1. Field of the Invention
The present general inventive concept relates to an image forming apparatus, and, more particularly, to a printing medium supply device capable of sequentially supplying printing media for the implementation of a sequential printing operation, and an image forming apparatus having the printing medium supply device.
2. Description of the Related Art
Generally, an image forming apparatus is an apparatus to develop a black-and-white image or color image on a printing medium, such as a sheet of paper, on the basis of an image signal. Examples of the image forming apparatus include a laser printer, an ink-jet printer, a copying machine, a multi-function machine, facsimile, etc. Representative image forming methods of these various kinds of image forming apparatuses include an electro-photographic method and an ink-jet method. In the electro-photographic method, a light beam is scanned onto a photosensitive member so as to form an electrostatic latent image, and a toner is attached onto the electrostatic latent image to transfer the electrostatic latent image onto a printing medium. In the ink-jet method, liquid-phase ink is ejected onto a surface of a printing medium on the basis of an image signal.
The above mentioned image forming apparatuses commonly comprise a printing medium supply device for storing a plurality of printing media therein and sequentially supplying the printing media for the implementation of a sequential printing operation. The printing medium supply device is detachably coupled to the bottom of an image forming apparatus body, and is used to supply the printing medium to an electro-photographic or ink-jet type printing engine that is installed in the image forming apparatus body. The printing medium supply device includes a frame coupled to the image forming apparatus body, and a loading plate installed in the frame and used to load the printing medium thereon. The loading plate serves to lift the printing medium, loaded thereon, toward a pickup device that is also installed in the image forming apparatus body.
When a printing operation begins, the pickup device picks up the printing medium, loaded on the loading plate, one by one, and conveys the picked-up printing medium to the printing engine. However, if the printing medium loaded on the loading plate has an incorrect alignment when being picked up by the pickup device, it may cause certain errors, for example, skew, a double pick-up, and/or a jam of the printing medium.
To solve the above problem, the loading plate is provided with a printing medium guide for the alignment of the printing medium. The printing medium guide is installed on the loading plate such that it can be manually moved by the user's operation. After loading of the printing medium, the user is able to align the loaded printing medium by moving the printing medium guide.
However, the above described conventional printing medium supply device is troublesome in use because the user has to operate the printing medium guide every time after loading the printing medium. If the user carelessly forgets to operate the printing medium guide after loading the printing medium, the loaded printing medium could be incorrectly aligned, thus causing certain errors, for example, a skew, a double pick-up, and/or a jam of the printing medium. These errors, caused during the conveyance of the printing medium, may result in deterioration in printing quality, waste of the printing medium, and malfunction of the image forming apparatus.